The United States has ended temporary flight restrictions over parts of the Caribbean that were imposed following its military operation in Venezuela, clearing the way for airlines to gradually resume service after widespread disruptions.

Transportation Secretary Sean Duffy said on Saturday that the airspace limits would expire at midnight Eastern Time, allowing carriers to begin restoring routes as schedules are adjusted. The restrictions had led to hundreds of canceled flights after U.S. forces carried out an operation that resulted in the capture of Venezuelan President Nicolás Maduro.

Major airlines quickly moved to restart services. United Airlines said it planned to operate a flight to San Juan, Puerto Rico, late Saturday and expected most Caribbean routes to resume on Sunday. Delta Air Lines said it anticipated returning to its regular schedule, though aircraft had been repositioned to manage earlier disruptions. American Airlines said it was preparing for the reopening of eastern Caribbean airspace and added thousands of extra seats to help accommodate delayed travelers, using larger aircraft where possible.

Spirit Airlines said it resumed flights to and from the Caribbean on January 4 following the expiration of the Federal Aviation Administration’s closure directive. JetBlue, which had canceled more than 200 flights, said it would also return to normal operations.

Even with the airspace reopening, airlines warned that normal service would not be restored immediately. Airline analyst Robert Mann said carriers were dealing with significant backlogs after a full day of stranded passengers across the region.

The FAA said the closures were ordered “due to safety-of-flight risks associated with ongoing military activity.” It also issued separate advisories warning non-U.S. airlines to avoid Venezuelan airspace. British aviation authorities cautioned operators of heightened risks from military activity near Venezuela, including the potential presence of anti-aircraft weapons.

Several international carriers in Europe and South America canceled or adjusted flights in response to the warnings. Flight tracking data showed that commercial air traffic over Venezuela largely halted after the U.S. operation.

Air Canada said its Caribbean and South American flights were operating normally under guidance from Canadian authorities but that it continued to monitor the situation.

The restrictions followed President Donald Trump’s announcement that U.S. forces had captured Maduro and that Washington intended to oversee Venezuela during a transitional period. The operation triggered regional aviation disruptions and raised concerns among airlines and regulators about safety in the airspace surrounding Venezuela.